1) Open SQL Developer then load the Schema_creation.sql and table_population.sql scripts to create and populate the tables discussed in assignment I. Open a new SQL worksheet then write the PL/SQL code that creates the following objects. 2) Create in PL/SQL a stored procedure called 'Del_Details' to delete the record of orderedProduct table for which it receives as input the order number (orderNO) and the product number (productNO). [1.5] 3) Create in PL/SQL a stored Function called 'productPerOrder' to return the number of products placed for any order its number is given as input. [1.5] 4) Write a Trigger called changeCustomer_Category. This trigger should be invoked before any update of customer balance in customer table. Its job is to modify the category of a customer from B2 to B1 and from C2 to C1 when a customer's balance status drops below a certain threshold (-10000).[2]